In geometry, a translation is the shifting of a figure from one place to another without rotating, reflecting or changing its size. This is done by moving the vertices of the figure the prescribed number of spaces on a coordinate plane and then drawing the new figure.
These PFDs are designed to keep the wearer in a vertical position, but it is the wearersâ responsibility to maneuver themselves into a face-up position. Type III PFDs will keep unconscious wearers face-up just as well as a Type II vest.
While these two methods both occur when you're surrounded by air, immersion of your face and/or body into water provokes the so called mammalian effect. This is what freediving is all about, and here you take advantage of the mammalian effect in order to hold your breath for long times under water.